Chinked style log homes are purposely built with a space between each course of log work. This space is filled with a backer rod and then chinking is applied both inside and out. Modern chinking has great adhesion and elastomeric (it’s got good stretchability) properties, allowing it to expand and contract as the logs move.
Caulk (the term ‘sealant’ is often used interchangably), is used to seal checks and cracks that may permit rain or insects to penetrate down into the logs and timbers, around doors and windows, and between walls and roof…anywhere you’ve got air infilatration (this applies to log, timberframe, post and beam and regular stick built construction). A wide range of colors allows you to match the color of finish you use.